Lindsay Lohan is the last person you'd expect to be giving pregnancy advice.

But in her new movie, the actress dons a floral pregnancy smock for the cover of a self-help guide for mothers-to-be, entitled 'I'm So Over This: What It's Really Like To Be Pregnant.

Her character appears to be giving pregnancy advice to expectant mothers - despite only pretending to be 'with child' in a bid to keep her job.

Would you take advice from Hollywood hellraiser Lindsay? The actress poses with her prosthetic bump

Despite her huge baby bump on the cover, Lindsay hasn't been hiding a pregnancy - she was simply wearing a prosthetic stomach for her new film Labor Pains.

The 22-year-old looked swell over the weekend as she filmed her role as a young publishing assistant who fakes a pregnancy so her bosses can't fire her.

Labor Pains marks Lindsay's return to the big screen after her flop thriller I Know Who Killed Me last year.

That's a fine bump: Lindsay Lohan shows off her prosthetic bump on the set of Labor Pains in Encino, California

In recent years, critics have claimed Lindsay has been gaining more attention for her personal life than her acting.

After a drink driving arrest in 2006 and several spells in rehab, Lindsay is determined to prove her critics wrong and show off the acting ability that wowed audiences in Mean Girls and Freaky Friday.

On set on Labor Pains in Encino, California, on Friday, Lindsay filmed a romantic screen with co-star Luke Kirby.

Kiss off: Lindsay Lohan puckers up for an on-screen smooch with co-star Luke Kirby

During the scene, the couple smooched for the cameras, while Luke gropped the actress's chest.

Lindsay has been filming the movie for the last two weeks after returning from the Cannes Film Festival last month, where she caused a storm with her public displays of affection with rumoured girlfriend, DJ Samantha Ronson.

Samantha has been constantly at Lindsay's side over recent months and visited Lindsay on set on Friday.

Baby bump: Lindsay Lohan studies her prosthetic bump on a sunny day in California